1. Field of the Invention
This invention relates to improvements in cameras, and more particularly, but not by way of limitation, to a motion picture device adapted to move the film therethrough in intermittent stop-and-go motion and containing an improved film drive system for effecting such movement at exceptionally high speeds.
2. Description of the Prior Art
Heretofore, high-speed motion picture cameras in which the film is advanced intermittently, one frame at a time, have been beset by many difficulties and problems. One of the major problems with such high-speed picture cameras resides in the need for overcoming the inertia as the film and associated parts are caused to accelerate between the stop-and-go operations. This change of inertia not only causes the need for additional energy to be placed in the system, but also places a heavy strain on all of the moving parts. Accordingly, it is desirable to minimize the number of moving elements which undergo such rapid changes in velocity during the stop-and-go movement of the film through the film gate.
In addition, other operational areas of cameras of this type are constantly in need of further improvement, when possible, and these include the film drive mechanism whereby it is desirable to achieve high-speed operation with a minimum of power, and yet provide for synchronized movement of the irregular relationship between the supply reel and the take-up reel. Accordingly, it is desirable to utilize a minimum of moving parts in such drive, yet provide reliable operation, and facility of use, i.e. change of reels for use of the camera with multiple reels at one time.
Another problem that has arisen in motion picture cameras resides in the tendency of the film to bow somewhat so that a cylindrical concavity appears on the emulsion side of the film. It is therefore desirable to provide a film gate that tends to flatten out the film so as to provide a better focal plane at the film gate, yet which does not injure the emulsion or provide undue frictional drag as the film passes through the gate.